The present invention relates to surgical instruments, and particularly to guides for saw blades used in bone resection.
During various surgical procedures such as implantation of prosthetic knee joints, ankle joints, shoulder joints, finger joints, etc., it is often necessary to make cuts or resections of bone in order for the prosthetic device to be implanted. Typically, these resection procedures involve connecting cutting blocks to the bone using intermedulary rods, screws or the like, and resecting portions of the bone by cutting along a guide path defined by guides that are formed in the cutting blocks. The guide paths formed in the cutting block guide the surgeon's saw blade in a predetermined direction, usually along a straight line, with respect to the mounted cutting block. Once the bone has been properly resected in the appropriate locations, the prosthetic device can then be secured to the bone and the implantation procedure can be completed.
The prior art includes different types of guides for producing a cut or resection in an anatomical structure relative to some reference plane or line. See, for example, U.S. Pat. No. 4,738,253 and U.S. Des. Pat. Nos. 272,853 and 272,854. However, the guides that are currently known have a number of problems. For example, some of the current cutting guides include a single guide surface (made of stainless steel or the like) upon which a saw blade rests as the saw blade is reciprocated or oscillated along the cutting path. As the resection is being made, the saw blade is pressed against the single-sided guide surface and the saw blade has a tendency to bend or bow as the resection is being made. To solve this problem, more recent guides include slots for guiding the saw blade. The saw blade is thus bounded on both sides and can reciprocate within the slot so that the amount of saw blade bowing is minimized.
However, both single-sided guides and slot guides currently in use include a smooth guide surface (or surfaces), usually made of stainless steel, upon which the saw blade travels as it reciprocates or oscillates along the desired cut path. As a result, the saw blade has a tendency to bind or gall against the smooth surface because there is a lot of friction. This in turn causes the bone resections to be less accurate and more difficult because the saw blade is over-stressed. Thus, surgeons who perform bone resections would appreciate a cutting block that included a low-friction guide surface because the bone could be resected more easily and more accurately if the saw blade did not bind, gall, or bow.